Vehicle electrical system

Abstract

A vehicle electrical system includes a battery, a customer connection point, a switch electrically connected in series between the battery and the customer connection point, a solar panel electrically connected to a node between the battery and the switch, and a computer communicatively coupled to the switch. The computer is programmed to instruct the switch to close upon determining that a voltage of the solar panel is greater than a voltage of the battery.

The invention claimed is: 
     
       1. A vehicle electrical system comprising:
 a first battery; 
 an ignition electrically connected to the first battery, wherein the first battery is configured to supply power to a starter in response to a signal from the ignition; 
 a second battery; 
 a customer connection point, wherein the customer connection point is a feature to which a nonvehicle load is electrically connectable; 
 a first switch electrically connected in series between the first battery and the second battery; 
 a second switch electrically connected in series between the second battery and the customer connection point; 
 a solar panel electrically connected to a node between the second battery and the second switch; and 
 a computer communicatively coupled to the second switch, the computer being programmed to instruct the second switch to close upon determining that a voltage of the solar panel is greater than a voltage of the second battery. 
 
     
     
       2. The vehicle electrical system of  claim 1 , wherein the computer is further programmed to instruct the first switch to close upon determining that the voltage of the second battery is less than a voltage of the first battery. 
     
     
       3. The vehicle electrical system of  claim 1 , wherein the computer is further programmed to instruct the first switch to open upon determining that the voltage of the second battery is at least equal to a voltage of the first battery. 
     
     
       4. The vehicle electrical system of  claim 1 , wherein the first switch is electrically connected in series between the first battery and the second switch. 
     
     
       5. The vehicle electrical system of  claim 1 , further comprising a third switch, wherein the third switch is a double-throw switch switchable among (1) closed to the first battery, (2) closed to the customer connection point, and (3) open. 
     
     
       6. The vehicle electrical system of  claim 5 , wherein the computer is further programmed to instruct the third switch to close to the customer connection point upon determining that the voltage of the solar panel is greater than the voltage of the second battery. 
     
     
       7. The vehicle electrical system of  claim 5 , wherein the computer is further programmed to instruct the third switch to close to the first battery upon determining that a state of charge of the first battery is less than fully charged. 
     
     
       8. The vehicle electrical system of  claim 5 , wherein the computer is further programmed to instruct the third switch to open upon determining both that the voltage of the solar panel is less than the voltage of the second battery and that a state of charge of the first battery is fully charged. 
     
     
       9. The vehicle electrical system of  claim 1 , wherein the computer is further programmed to instruct the second switch to close upon determining that a state of charge of the second battery is above a charge threshold. 
     
     
       10. The vehicle electrical system of  claim 1 , wherein the computer is further programmed to instruct the second switch to open upon determining that a state of charge of the second battery is below a charge threshold. 
     
     
       11. The vehicle electrical system of  claim 1 , wherein the computer is further programmed to instruct the second switch to open upon determining both that the voltage of the solar panel is greater than the voltage of the second battery and that a state of charge of the second battery is below a charge threshold. 
     
     
       12. The vehicle electrical system of  claim 1 , further comprising a plurality of customer connection points including the customer connection point, wherein the second switch is electrically connected in series between the second battery and the plurality of customer connection points. 
     
     
       13. The vehicle electrical system of  claim 12 , wherein the computer is further programmed to receive an input selecting a target time, select a subset of a plurality of nonvehicle loads electrically coupled to the customer connection points upon predicting that the second battery will discharge to a charge threshold before the target time, and then transmit instructions to the subset of the nonvehicle loads to shut down. 
     
     
       14. A vehicle electrical system comprising:
 a battery; 
 a plurality of customer connection points, wherein the customer connection points are features to which nonvehicle loads are electrically connectable; 
 a switch electrically connected in series between the battery and the plurality of customer connection points; 
 a solar panel electrically connected to a node between the battery and the switch; and 
 a computer communicatively coupled to the switch, the computer being programmed to: 
 instruct the switch to close upon determining that a voltage of the solar panel is greater than a voltage of the battery; 
 receive an input selecting a target time; 
 select a subset of a plurality of loads electrically coupled to the customer connection points upon predicting that the battery will discharge to a charge threshold before the target time; and 
 then transmit instructions to the subset of the loads to shut down. 
 
     
     
       15. The vehicle electrical system of  claim 14 , wherein selecting the subset of the nonvehicle loads is based on power-consumption data received from the nonvehicle loads. 
     
     
       16. The vehicle electrical system of  claim 15 , further comprising a wireless transceiver communicatively coupled to the computer, wherein the computer is further programmed to receive the power-consumption data from the nonvehicle loads via the wireless transceiver. 
     
     
       17. The vehicle electrical system of  claim 15 , wherein the power-consumption data includes individual rates of power consumption of the nonvehicle loads. 
     
     
       18. The vehicle electrical system of  claim 14 , further comprising a transceiver communicatively coupled to the computer, wherein the computer is further programmed to instruct the transceiver to transmit a message to a remote server upon predicting that the battery will discharge to the charge threshold before the target time. 
     
     
       19. A vehicle electrical system comprising:
 a first battery; 
 a second battery; 
 a customer connection point, wherein the customer connection point is a feature to which a nonvehicle load is electrically connectable; 
 a first switch electrically connected in series between the first battery and the second battery; 
 a second switch electrically connected in series between the second battery and the customer connection point; 
 a solar panel electrically connected to a node between the second battery and the second switch; and 
 a computer communicatively coupled to the second switch, the computer being programmed to: 
 instruct the second switch to close upon determining that a voltage of the solar panel is greater than a voltage of the second battery; and 
 instruct the first switch to close upon determining that the voltage of the second battery is less than a voltage of the first battery. 
 
     
     
       20. The vehicle electrical system of  claim 14 , wherein selecting the subset of the nonvehicle loads is based on a prioritization of the nonvehicle loads received as an input.